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CIRCUIT CHANGER. 110.368,'221. Patented Aug. 16, 1887.

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UNITED STATES PATENT OEEIcEo CHARLES 7. MCDANIEL, OF KANSAS CITY,MISSOURI.

CIRCUIT-CHANGER.

SPECIFICATION forming part of Letters Patent No. 368,221, dated August16,1887, Application filed February 17, 1887. Serial No. @7.925. (Nomodel.)

T all whom, t may' concern:

Be itknown that I, CrmELEs W. MCDANIEL, of Kansas City, in the county ofJackson and State of Missouri, have invented certain Improvements inCircuit-Changers, of which the following is a specification.

My invention relates to switches or circuitchangers, and its object isto furnish a novel and convenient loop-circuit changer capable of beingefliciently used in a large variety of ways in connection withelectrical circuits and appliances.

In consists of two segmental faces of metalseparatedbyaninsulatingmedium,which,how ever, unites the twoconducting-faces mechanically, and mounted in pivots or bearings betweencontact-springs upon a suitable nonconducting base. The metal sides mayeach, by means of suitable screw or soldered connections, constitutepermanently the respective terminals of a loop of an electric circuit orofthe two wires of a metallic circuit of any character. Upon the samebase, at opposite sides thereof, I mount two pairs of contactsprings,w'ith which the loop-terminals, as represented by the metallic segments,may be brought into contact by swinging the said segments to one side orthe other. The two springs of each pair are separated by an airspaceslightly less than the thickness of the movable piece, including the twoconductingfaces thereof and the insulating-partition, and they slightlyilare at the ends, so that the end of said movable piece can be readilyinserted between them and force them apart. When swung toward eitherpair, one of the segments comes into contact with onespringand the othersegment with the other spring of a pair. An arm of the two segments andtheir separating non-conductor extends upward to serve as a handle,whereby the switch may be swung; and an opposite arm extends from theinner side of the segmental curve downward and receives the pivotalscrews or bearings on which the segments may be moved. An extracontact-spring extends from each pivot-screw or from the standardthereof, and passes with a rubbing contact upon the metal segments, ir-

respective of the position thereof. One of the arms of the segment islonger than the other, so that when the switch is turned in onedirection the handle7 which is thus placed on one side of the center ofthe segments, will assume a vertical position, which may indicate thenormal condition ofthe switch. When oppositely turned, the handle pointsto an angle with the base, and in like manner may indicate the abnormalcondition of the switch. This switch is readily capable ol" employmentas a pole-changer or current-reverser, a cutout, a telephone looping-inswitch, a single or double ordinary th ree-point switch, or a switchwhereby either of two lines may readily be connected to either of twoinstruments, or vice versa.

Many otherutilizations of my circuit-changer will readily suggestthemselves to those skilled in the art. Y

I have in the drawings which illustrate and constitute a part of thisspecification shown several views of my circuit-changer and diagrams ofdifferent plans of using the same.

Figure l is a perspective view, and Fig. ln a side elevation, or" thecircuit-changer. Fig. 2 is a vertical end section of the same, and Fig.3 an end view of one of the pairs of contact-springs. Fig. 4 is a planView. Fig. 5 shows the mode of applying my switch as a pole-changer orcurrent-reverser for use in electrical measurements or likeapplications, and Fig. 6 is a cut-out for electrical communicatingapparatus. Fig. 7 illustrates its application for the reciprocal use oftwo sets of instruments by either of two lines. Fig. 8 shows itsapplication to telephone switchboards, and Figs. 9 and 10 indicatesymbolically and respectively the use of my circuitchanger as anordinary single or double threepoint77 switch.

In describing the construction of the switch, reference will be had toFigs. l, la, 2, 3, and 4.

In the drawings the appliance is mounted upon a base, l, of hard rubber,hard wood, vulcanized ber, or like non-conducting matcrial. Upon thisand near the center cf its sides a pair of standards, 2 and 3, areattached by screws. Vithin and upon these standards is hung the movablepa-rt C ef the circuitchanger, comprising two polished metalconducting-surfaces, 7 and 8, separated from one another electrically bya non-conducting partition, t', to which both surfaces are, however,mechanically fixed by machine-screws,or in any preferred way. rlhe shapeof this mova- IOO ble part C is generally segmental, but said part hastwo vertical extensions, one of which, it, projects outwardly from theconvex side of the segment to serve as a handle, while the other extendsdownwardly from the concave side of the segment and is mounted onpivots. This second projecting arm does not include the insulatingmedium, which is cut away, and comprises, therefore, the two metalsurfaces only, their ends being indicated by the letters w and x.Through the verti cal portion of the standards .2 and 3 pivot-screws 11and 12 are inserted, which project into recesses or bearings in thedownward extensions w :l: of the metal surfaces 7 and 8 of the switch,and upon the ends of these screws the movable part of the said switch iscapable of being rocked by means of theupwardly-extending arm 4, whichserves as a handle.

Two metal contact-springs, S) and 10, are attached (by solder orotherwise, so as to make a good electrical connection) to the upper endsof the brackets or standards 2 and 3, and press at their free ends uponthe bright metal surfaces 7 and S, so that perfect electrical con`tinuity is at all times maintained between the said surfaces and thestandards they are pivoted in.

Electrical wires 30 and S1 may be attached to the screws s, which securethe standards to the base, and the two surfaces 7 and 8 thus constituteterminal plates for the circuit-loop represented by the said wires. Thearms 4t and iv x, extending from the segmental movable part, do notproject from a point equidistant between the two ends of the saidmovable part, but are much nearer' one end of vthem than the other, asshown. By this construction it is made easy to see at a glance whetherthe circuit-changer is or is not in its normal position, as when theswitch is thrown to one side the arm assumes a vertical position, whilewhen the switch is oppositely placed the arm assumes a position at anangle to the vertical plane. Furthermore, this handle thus divides thesegment into two arms, a longer arm, 5, and a shorter arm, 6. At eachend of the base, in liuc with the movable part C, are a pair ol'spring-jaws, 13 14 and 15 16. These are shown in detail in Fig.3,and thetwo springs oleach pair are so placed with respect to one another and tothe movable part C that when the latter is swung between them it forcestheir ends farther apart from one another and brings the spring 15, forinstance, into frictional contact with the metal surface of theside Sand the spring 16 into contact with the metal surface 7 The spacebetween the spring ends 15 and 16 is normally smaller than the thicknessof the movable part C, which is introduced between them, so that a goodelectrical union is always maintained. Moreover, the ends of bothsprings are slightly bent backward, while at the same time the end ofthe segmental arms 5 and 6 are slightly tapered off at their eX-tremities, so as to facilitate ingress between the springs 15 and 16, ortheir congeners at the opposite end. Circuit-wires 22 27 areattaehed tothese springs, and the two pairs of springs thus may be made toconstitute auxiliary loops, which may include signaling appliances orother instruments, or which may, if desired, form the terminals ofextensions of the principal circuit. It is thus evident that by turningthe handle -1 in either direction the circuit with which the metalsegments are connected may readily be continued through the springs uponthat side to an extension-loop for any desired purpose.

I will now describe a few of the uses to which my invention may beapplied, having reference to the diagrams, Figs. 5, 6, 7, S, 9, and 10.

ln Fig. 5 its extreme convenience as a quick andefficientcul-rent-reverser or pole-changer is manifested. changer isshown symbolically. As a whole, the circuit-changer is designated in thediagrams by the letter A. In Fig. 5 a battery, B, has one of its polesunited by wire 26 with one of the jaw-springs1 1i, at one end and sideof the base, and also with asimilar spring, 15, at the other end andside of the base. The other pole of the same battery is in like mannerunited by wire 17 with the remaining jawsprings, 1G and 13. One of theside springs, 9, is united by wire 30 with one terminal of the rheostatN, while the other side spring, 10, is united by wire 3l with oneterminal of the galvanometer Gv. The remaining terminals of thegalvanometer and the rheostat are united by thewire 23. It is obviousthat the current ofthe battery B is readily reversed with respect to theinstruments N and G simply by swinging the switch C over from thesprings 13 and 14C to the springs 15 and 1,6, or vice versa. Therheostat and galvanometer are obviously replaceable by any otherappliances responsive'to changes of direction of an electricalcurrent-such, l'or example, as a mainline circuit and one or morepolarized relays.

In Fig. 6 the operation ofthe circuit-changer A as a cut-out isexemplified. A is the circuitchanger, G the movable part thereof, 9 and10 the side springs connecting with the movable conducti11g-surfaces,and l 3 1l and 15 16 the end jaw-springs. A main line, 3l, terminates incontact with the side spring, 10, anda ground-wire or return-wire, 30,of the said main line with the side spring, t. The two jaw-springs 13and 14C at one end (which end is immaterial) are united by a wire, 20.The two jaw-springs 15 and 16 at the other end are united by wires 22and 27 with the terminals of the telephone outfit H or any other desiredinstrument. \'Vl1en the movable part C is turned toward springs 15 and16, it is clear that the instruments are thereby introduced into theline-circuit, while when the movable part C is turned to the springs 13and 14 the instruments H are thereby cut out and' the two sides of themain circuit are closed through springs 13 and 1-t and wire 20. Inpractice, when employed Vfor this purpose, l

In these diagrams the circuit- EOO IUS

IlO

preferably mount the appliance upon the side of the magneto-bell. It isto be observed, moreover, that this device constitutes a perfect cut-outor disconnector, and not merely a shunt-circuit, as is the case in theordinary plan where a plug is inserted between two contact-plates.

The advantages accruing from the use of my circuit-changer are, first,that the apparatus H may be totally disconnected, and hence is notsubject to danger from abnormally strong currents or charges ofelectricity passing in the main circuit, and, second, that there is nochance for a subscriber to cut out his apparatus (foreXaniple,duringathunder-storm) and, forgetting to cut it in again, toassume that his line is out of order, on the ground that as he hears thebell ring when he sends a call his apparatusis in Working order. Vhen ashort circuiting plug only is used, this defect neces sarily exists; butif the subscriber in using my device forgets to cut in his apparatus hisbell Will not ring at all when he essays to call a distant station, itscircuit being open at the springs 15 and 16; hence his attention isimmediately attracted to the cut-out, which he then operates toreconnect his apparatus.

Fig. 7 shows the solution by my circuitchanger of a well-known andever-recurring.

problem. It frequently happens that at one sub-station two lines center,with which, for economy, it is desired to associate but one set oftelephones. It is, moreover, desirable that the line, which at anymoment is disconnected from the principal call-bell, callgenerator, andtelephone, shall be provided with a call-bell ofits own, so that signalscoming over that line shall .not pass unnoticed. It is also desirablethat the act of transferring the telephones from either line to theother shall reciprocally transferalso the auxiliary bell to the linefrom which the telephones and principal call apparatus aresimultaneously withdrawn. In the accomplishment of this end my applianceis a very convenient device. One line, L, connects by wire 22 with thejaw-spring at one end and side, 13, and also with a similar spring, 16,at the other end and side. The other main line, D, is permanently unitedby wire 27 with the remaining jaw-springs, 14 and 15. The telephone-callgenerator and principal bell may be connected with one of the sidesprings, 10, by wire 31, and on the other side with the earth at T, andthe auX- iliary call -bell E is then united by one terminal through wire30 with the other side spring, 9, and by the terminal also with theearth at T. Suppose nour the circuit-changer is turned toward thesprings 13 and 14. The line L may be traced through wire 22 to spring13, metal surface 7 of the movable part C, spring 9, and wire 30 to theauxiliary call-bell and ground. The other line, D, may be in like mannertraced from wire 27 to spring 14, movable conducting-surface 8, sidespring, 10, and wire 31 to main call-bell and telephones and thence toearth. Thus the line D is in condition either for signaling ortalking,while the line L is in connection with a call-receivinginstrument only; but by pulling the handle 4 over toward the springs 15and 16 the conditions may be reversed, line L being connectedwith thetelephone outfit and line D with the auxiliary bell.

In Fig. 8 my appliance is represented as being utilized as a loopingappliance, whereby a double line or two connected lines may bealternatively made to include an annunciator, a, or telephones. Thisorganization lnds its special iield of operation in connection withtelephone switch-boards. When two lines are united through a telephoneswitchboard, or when the lines are at rest, it is often necessary tointroduce the operators instruments into the circuit for the purposes oforal communi cation, supervision, or signaling. It is also equallyconvenient, and is, moreover, customary, to provide an annunciatorbetween the two connected line circuits or between any given line andits return or earth terminal, whereby to receive disconnecting signals.My invention is particularly well adapted for this purpose. Twoconnecting-plugs, p p', are adapted for insertion into switch-boardsockets or springiacks, each representing lines, in a manner wellunderstood. The jaw-springs 13 and 14 at one end of the base are unitedby wires 22 and 27 with the electro-magnet of an annunciator, u. Theother two jaw-springs, 15 and 16, constitute the terminals of a loopincluding, by means of the wires 29, 30, and 31, the calling apparatusG2 and telephones P and M. Asmallswitch, S, determines byits positionthe alternative use ofthese instru mentalities. The connecting-plugsp pare united by flexible conductors 28 and 28 with the side IOO springs?)and 10. When itis desired to send calls to either line, to speak overeither line, orto supervise con versation, the handle 4 ofthecircuitchanger will be turned toward the springs 15 and 16. The maincircuit may then be traced from plug p cia cord 28 to side spring, 9,metal surface 7, `jaw-spring 15, wires 30 and 31, telephone or callinstruments, wire 29, j aw-spri ng 16, metal surface 8, side spring, 10,and iiexible cord 28 to plug p. The line 2, 'connecting the plug-socketslc le', represents the united lines. When the switch is in thiscondition, communication may be maintained between the central stationand the two lines; but when it is desired to withdraw the centraltelephones from the lines, the handle 4 is thrown over toward thesprings 13 and 14, the telephones thus being disconnected and adisconnectingannunciator, a, substituted therefor. In this applicationof my circuit-changer it is obvious that but one telephoneloop isnecessary, eX- tended, asindicated in the drawings, to as manynormally-open terminals 15 16 as there are pairs of plugs and cords forconnecting.

It will be seen by reference to Figs. 1 and 1a that the movableconducting-segment C is so IIO IIS

long that it makes contact upon one side before it breaks contact uponthe other. This is in many respects advantageous. It prevents amomentary interruption of communication at the instant et' change. lfemployed in systems using heavy currents, it averts all danger ofsparking at the contacts, and it enables a telcphone-operator, if he sodesires, lo listen in without breaking the back circuit, thus giving tworoutes to the talking-current and reducing the resistance, instead ofincreasing it.

ln Figs. 9 and l() the functions of an ordinary single and double switchare indicated. In the single form, Fig. 9, the main circuit enters atthe binding-screw c, and leads by wire 45 to both side plates, 9 and l0.One of the brauch circuits enters at the bindi iig-screw and leads bywire 4] to the twin jaw-springs l5 and 1 6, which are electricallyunited. The other branch circuit enters at d and passes by wire li3 tothe two oppositejaw-springs 13 and l-it. The main wire 45 can thus beput into connection with either branch. Fig. l() is an extension ofthesame principle. Aside appliance is there, however, made to supply twomain circuits, connecting, respectively, with binding-screws j and rlhemain wire 50, leading from and connectedY with fi., can be united witheither of the branches Lif) or 51 at will, and the main line 47,represented by the screwterminalf, may similarly be united with eitherot' the branches itti 01H18. Each spring-contact has in this instanceits own screw-terminal.

Many other utilizations will readily occur to practical electricians.

"y using two-separate loop-levers on separate bases, or upon the samebase, a number of other combinations of circuits can be made.

One ofthe ai'lvantageous Afeatures of my circuit-changer is that all ofthe wire attachments are readily made upon its surface and are notconcealed in any way, but can be changed with the greatest facility.

I claim as my invention- 1. rlhehereinbcfore-described ci rcuit-changer,comprising a pivoted lever and curved arms and having twocondnoting-surfaces insulated from one another, brackets or standards inwhich the said lever is pivoted, each bracket constituting acircuit-terminal and being provided with a spring bearing upon one ofthe conductiiig-surfaces of the said lever, and two pairs oticontact-springs, one Vfor each leverarm, each pair of springs beingadapted'to be connected with one or more independent branch circuits andmounted in the line of movement of the two arms of the said lever,whereby when the said' lever is swung on its pivots in either directionits insulated condncti 11g-surfaces are brought,respectively,intoelectrical connection with the two springs of a pair, substantially asand for the purposes specified.

2. The combination, substantially as hereinbefore described, of atelephone loop-circuit,

including` telephone or call instruments,a pair of jaw-spring contactsconstituting the terminals of said loop-circuit, au independentloopcircuit including an electro-magnetic annunciator, a separate pairof jaw-spring contacts constituting the terminals of the second loop, amovable loop-lever mounted on pivots in standards located at a pointmidway between the two said pairs ot' jaw-springs and provided with ahandle to move the same in the direction of either pair, the saidloop-lever comprising two curved comlucting-plates separated from oneanother and mounted upon an insulating-block, cach ofthe said platesbeing in permanent contact, as specified,\vith springs forming theterminals of a third loop-circuit and adapted when moved in eitherdirection to wedge between and make contact, respectively, with the twojaw-springs, which lie in sa-id direction, whereby the thirdloop-circuit maybe united and made homogeneous with thc first or secondloop-circuits at will, and l'or the purposes specified.

rlhe combination, substantially as herein described, of a non-conductingbase, two bairs of conducting-springs mounted thereon and forming loopor branch circuit terminals, as indicated herein, a movable piecemounted on pivots or journals on standards upon thcsamc base between thesaid pairs ofsprings and equidistant from each pair, the said movablepiece consisting of two `llat curved contact-plates attached to thesides of a non-conducting intervening plate and having a handle wherebyit may be swung on its pivots in either` direction, and being of alength slightly Alonger than the distance between the pairs of springs,whereby when swung in either direction the curved contact-plates areenabled to make contact with one pair of springs before they aredisconnected from the other, and contactsprings constituting theterminals of a separate circuit pressing at all times upon the flatconducting-suriccs of the movable piece irrespective of the position ofthe said movable piece, for the purposes specified.

4. In a switch or circuit changer, the combination of two pairs ofcontact springs mounted upon a common basc,the two springs of each pairforming or adapted to form loop or branch circuit terminals, a movablepiece consisting of two curved conducting surfaces mounted upon thesides of a similarly conformed nonconducting partition and mechanicallyunited thereby, the said movable piece being hung upon pivots orjournals in standards `placed intermediately between the pairs ofcontact-springs, which standards also constitute circuit-tcrminals, andadapted to be swungin either di rcetion,and thereupon to connect its twoconducting-surfaces with the two springs of the pair in such directionand to disconnect them from the other pair, and contact-springspermanently in electrical union with the s upporting-standards of thesaid movable piece and bearing with frictional con- IIO tact upon thetwo conducting-surfaces thereof, to this specicatiornin the presence oftwo subas described, irrespective of the'position of scribing Witnesses,this 9th day of February, Io said surfaces, whereby the loops orbranches 1887. terminating in the paired springs may be con- 5 nectedwith or disconnected from the circuit represented by the movable piece,substan- Witnesses: tially as described. I RoDNEY FERGUSON,

In testimony whereof I have signed my name l C. D. CRANDALL.

CHARLES WV. MCDANIEL.

